This project is concerned with demonstrating the immunochemical specificity of hypersensitivity reactions to penicillins and cephalosporins, especially reactions thought to be due to cell-mediated immunity. Two aspects are currently being investigated: (1) Synthesis of immunochemically defined polymers and hapten-substituted carriers of differing sidchain and nuclear configurations, in order to study the specificity of immunological reactions; and (2) in vitro assays of cell-mediated immunity, with emphasis on the agarose assay of leukocyte migration inhibition, in which the mechanism of polymorphonuclear leukocyte migration is being investigated as are the nature and quantative aspects of the inhibitory signals released by antigen-specific lymphocytes. The project involved producing an experimental model of cell mediated immunity to Beta-lactam antibiotics, and includes study of patients experiencing clinical hypersensitivity reactions of all types to Beta-lactam antibiotics.